Carrier Ethernet refers to the use of Ethernet frames as a transport mechanism within a backbone network, which connects any number of edge networks, such as enterprise networks, local area networks, subscriber networks, residences, and the like. The backbone networks are generally used to support wide area or metropolitan area networking between these edge networks. The rationale for using Ethernet within backbone networks is plentiful. Most local area networks (LANs), networking devices, and networked user terminals in the edge networks rely on Ethernet as a transport mechanism, which generally refers to a defined data link layer technology. As such, the use of Ethernet in the edge networks is ubiquitous and data within these edge networks is carried in Ethernet frames. By also using Ethernet frames in the backbone networks that connect the edge networks, the frames in edge and backbone networks are compatible with each other and frame conversion is avoided. If the backbone network does not employ Ethernet, the frames must be converted from one transport mechanism to another each time a boundary between an edge and backbone networks is crossed. Carrier Ethernet also supports high network access speeds, as the Ethernet-based edge networks can be coupled directly to the backbone network with relative ease. Finally, the cost associated with Ethernet-based networks is relatively low given the mature, widespread, and large scale use of Ethernet equipment. For these reasons, there is a strong desire to employ Carrier Ethernet in backbone networks that support all types of communications, including data, voice, audio, and video.
Unfortunately, Carrier Ethernet does not provide substantially immediate recovery mechanisms when a networking device or link fails. Current recovery mechanisms include rerouting and other restoration techniques, which require the affected nodes to communicate with each other extensively to identify the failure and then either reroute traffic or attempt to correct the failure. The need for the nodes to communicate with each other to such a degree to identify and address the failure injects significant delay in the recovery mechanism. Delivery sensitive services that require high quality of service levels like telephony and television services are subject to unacceptably long dropouts when substantially immediate recovery mechanisms are not available. Currently, existing recovery mechanisms being employed for Carrier Ethernet take more than a few seconds and often 30 seconds or more to recover from a failure. In contrast, most telephony and television service providers require a recovery period of less than 50 milliseconds to ensure a customer is unaffected by a failure. Other types of transport technologies, such as traditional Synchronous Optical Network (SONET) infrastructures have built-in recovery mechanisms that are capable of recovering from a failure in less than 50 milliseconds; however, these technologies are generally much more costly than Carrier Ethernet and require undesirable interworking at network entry and exit. The absence of an acceptable recovery mechanism for Carrier Ethernet is posing a major barrier to employing Carrier Ethernet for a wider and more comprehensive range of services. As such, there is a need for an effective and efficient recovery mechanism for backbone networks that employ Carrier Ethernet and like transport mechanisms.